1. Field of the Invention
The present invention relates to a wireless mobile communication system. More particularly, the present invention relates to a method for performing a Hybrid Automatic Repeat reQuest (HARQ) operation in a wireless mobile communication system.
2. Description of the Related Art
Wireless mobile communication systems have been developed to provide a variety of services including a broadcasting service, a multimedia video service, a multimedia messages service, and the like. Future-generation wireless mobile communication systems are under development with the aim to provide a data service at or above 100 Mbps to fast moving users and at or above 1 Gbps to slowly moving users.
In a wireless mobile communication system, a reduced control overhead and a short latency are required for high-speed transmission and reception of reliable data between a Base Station (BS) and a Mobile Station (MS). In order to decrease control overhead and latency, a Hybrid Automatic Repeat reQuest (HARQ) technique may be employed.
When a transmitter transmits a signal carrying data to a receiver, the receiver feeds back an ACKnowledgment (ACK) signal indicating successful reception of the signal or a Negative ACK (NACK) signal indicating failed reception of the signal to the transmitter in a wireless mobile communication system implementing HARQ. Upon receipt of the ACK or NACK signal, the transmitter initially transmits new data or retransmits the transmitted data to the receiver according to an HARQ scheme. HARQ schemes may be categorized into two types, namely Chase Combining (CC) and Incremental Redundancy (IR).
Transmission and reception are performed on a frame basis during an HARQ operation, which does not decrease latency. Accordingly, a need exists for a new frame structure that shortens the latency of signal transmission and reception, and an HARQ operation timing structure for implementing the new frame structure.